This PDF file contains the front matter associated with SPIE Proceedings Volume 12868, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

Quantum information processing based on trapped ion technology is one of the leading platforms, heavily relying on a set of single-frequency lasers in its core operations. Narrow linewidth lasers perform atom photoionization, cooling, state-preparation and read-out. In this work we demonstrate in-house designed and fabricated optically pumped semiconductor laser gain mirror comprised of InGaAs quantum wells and GaAs/AlAs distributed Bragg reflector. We demonstrate in-house designed and fabricated single-frequency laser operating at 493 nm for Ba+ cooling. Inherent power scaling potential, efficient intracavity frequency conversion, coupled with sub-MHz linewidth and wide gain tuneability make VECSELs advantageous semiconductor laser platform for various quantum technology applications.

Membrane External-Cavity Surface-Emitting Lasers (MECSELs) are a new kind of vertically emitting semiconductor laser with enormous potential and versatility for tailoring the laser parameters. Part of their benefits is related to the fact that they do not need to employ integrated Distributed Bragg Reflectors (DBRs), which are known to hamper the heat transfer and limit wavelength versatility via strain and band-gap engineering constraints. Furthermore, the substrate on which the active region is grown on is removed and the resulting thin active region membrane is sandwiched between transparent Intra Cavity (IC) heat spreaders for improved thermal management. Initial characterization of room temperature operation of a new red emitting AlGaInP-based structure design containing 40 Quantum Wells (QWs) will be presented. Further, the main aspects of the design of active region membranes will be reviewed with respect to double-side pumping possibilities enabled by the absence of a DBR and the substrate. The comparably high cavity losses show future potential of a properly double-side pumped gain structure.

The phenomenon of Laue diffraction is known in crystallography. Conceptually, its optics resemble coherent forward scattering by a periodic refractive index structure. It has been shown that compact and efficient spatial filters within short solid-state laser cavities can be made utilizing the Laue diffraction approach. While manufacturing spatial filters based on Laue diffraction proves to be comparatively simpler than those relying on Bragg diffraction, challenges persist due to the typically three-dimensional nature of these structures. To simplify the implementation of such spatial filters, we present a new approach. We propose a new type of spatial filter based on the complex refractive index, namely an amplification grating built into a relatively short surface-emitting laser cavity with a semiconductor membrane external-cavity surface-emitting laser. This represents a very special case where we achieve this goal by self-imaging inside the resonator, creating a virtual photonic crystal spatial filter that increases the brightness of the output laser beam. The simplicity and effectiveness of this approach are thoroughly validated in our paper.

Mode-locked shared gain coupled VECSEL cavities exhibit novel lasing properties with dual cavities supporting independently running mode-locked fs pulse trains. Using an extended Maxwell – Semiconductor Bloch microscopic model, we show that initial simulations support experimentally observed independent mode-locking at separated wavelengths with little evidence for gain competition. Our extended SBE model expands the microscopic carrier populations and polarizations in a nonparaxial grating basis to capture large angle incident beams on the gain chip. Preliminary simulations support uncoupled mode-locking showing pulses simultaneously incident on the gain chip and we identify a novel independent mechanism for the wavelength selectivity.

One of the most promising candidates to use as compact high sensitivity magnetometers is the Nitrogen-Vacancy (NV) center, however traditional implementations of this technology are plagued by low collection efficiencies or poor signal contrasts of the Optically Detected Magnetic Resonance (ODMR). Laser Threshold Magnetometry (LTM) offers a path towards both efficient signal collection and high signal contrasts by taking advantage of near threshold laser dynamics. We demonstrate an infrared LTM using a Vertical External Cavity Surface Emitting Laser (VECSEL) with an intra cavity diamond plate doped with NV centers. The VECSEL was tuned to the spin dependent absorption line of the NV centers, which tied the VECSEL output power to the magnetic field sensed by the NV centers. Furthermore, the contrast and the projected sensitivity limit are shown to improve when operating close to the lasing threshold. We measure a sensitivity of 7.5 nT/√ Hz between 10-50 Hz with a contrast of 18.4% and a projected Photon Shot Noise Limited (PSNL) sensitivity of 26.6 pT/√ Hz close to threshold. We also observe a saturable absorption-like effect near threshold, which further enhances the signal contrast and projected PSNL near threshold. A rate equation model for the VECSEL threshold magnetometer is described and is fit to mimic the observed threshold dynamics.